Digenetic Trematodes in South American Sea Lions from Southern Brazilian Waters

Abstract

The aim of this work was to perform a systematic study to detect and quantify the digenetic trematode infections in South American sea lions from the southern Brazilian coast. Twenty-four South American sea lions, Otaria flavescens (Carnivora: Otaridae), were found dead along the coast of Rio Grande do Sul State, Brazil, between June 2010 and September of 2011. Two trematode species were found in the intestines of O. flavescens, i.e., Stephanoprora uruguayense (Digenea: Echinostomatidae) and Ascocotyle (Phagicola) longa (Digenea: Heterophyidae). Ascocotyle (P.) longa reached a prevalence of 33.3% and mean intensity of 248,500, whereas S. uruguayense showed a prevalence of 4.2% and mean intensity of 202. The 2 trematode species infecting sea lions were likely transmitted by feeding on mullets, Mugil platanus, that commonly harbor heterophyid metacercariae. The present work is the first report of digenetic trematodes infecting O. flavescens in Brazil. The high prevalence and mean intensity values of the 2 trematode species infecting sea lions in the present study suggest caution in human consumption of mullets and other fish, which can be infected with the metacercariae of these trematodes known to have zoonotic potential.

Gastrointestinal Parasites and Bacteria in Free-Living South American Sea Lions (Otaria flavescens) in Chilean Comau Fjord and New Host Record of a Diphyllobothrium scoticum-Like Cestode

“…South American sea lions (Otaria flavescens) belonging to family Otariidae are common carnivorous pinnipeds living along Eastern and Western coasts of South America. They are endemic in Argentina, Peru, South Brazil, and Chile (Vaz-Ferreira, 1982;Crespo, 1988;Túnez et al, 2008;Aznar et al, 2012;Hernández-Orts et al, 2013;Pereira et al, 2013). Along Chilean coastal shores, including Southern and Northern Patagonian fjords (Haussermann et al, 2014), more than 200 colonies of free-living South American sea lions were described.…”

A checklist of larval Digenea (Platyhelminthes: Trematoda) in molluscs from inland waters of Argentina: one hundred years of research

“…For instance, the genus Biomphalaria is found in Brazil (Ciccheto et al , 2021; Mesquita et al , 2021; among others) and F. hepatica is present in Bolivia and Brazil (Mas-Coma et al , 2020; Schwantes et al , 2020; Silva et al , 2020; among others). Moreover, some of the birds and mammals that act as definitive hosts, such as Otaria flavescens in Chile and Brazil (Pereira et al , 2013; Hermosilla et al , 2018), and Laurus dominicanus in Chile (Gonzalez-Acuna et al , 2009), are known to migrate in the southern part of the American continent. Cosmopolitan host species such as Physella acuta (Lawton et al , 2018; Pantoja et al , 2021) and migratory bird species from other continents are also in the checklist, making the present work of potential global interest.…”

Anthropozoonotic Parasites Circulating in Synanthropic and Pacific Colonies of South American Sea Lions (Otaria flavescens): Non-invasive Techniques Data and a Review of the Literature

“…Up to date, trematodes of the genera Ascocotyle (Morgades et al, 2006;Hernández-Orts et al, 2012;Pereira, 2012;Pereira et al, 2013), Lobatostoma (possibly fish parasite detected after gastrointestinal passage; Calderón-Mayo, 2015), Ogmogaster (George-Nascimento and Carvajal, 1981;Carvajal et al, 1983;Sepúlveda et al, 2015), Stephanoprora (Morgades et al, 2006;Pereira et al, 2013), and Zalophotrema (only one report in captivity; Petrov and Chertkova, 1963) have been reported for South American sea lions (Table 1). In the current study, eggs of two different trematode taxa were specified on clade level determined as Trematoda indet.…”